FIG. 1 illustrates a Relay Node (RN) 120 and User Equipments (UEs) 131 and 132 within the coverage of an evolved Node B (eNode B or eNB) 110 in a wireless communication system 100. The RN 120 may transmit data received from the eNode B 110 to the UE 132 within its relay coverage and data received from the UE 132 to the eNode B 110. The RN may also extend a high-data rate area, increase the communication quality of a cell edge, and support a communication service inside a building or in an area outside the coverage of the eNode B 110. In the illustrated case of FIG. 1, a UE (Macro-UE) that receives a service directly from the eNode B 110 such as the UE 131 co-exists with a UE (Relay-UE) that receives a service from the RN 120 such as the UE 132.
A radio link between an eNode B and an RN is called a backhaul link. A link directed from the eNode B to the RN and a link directed from the RN to the eNode B are called a backhaul downlink and a backhaul uplink, respectively. A radio link between an RN and a UE is called an access link. A link directed from the RN to the UE and a link directed from the UE to the RN are called an access downlink and an access uplink, respectively.
Although a downlink and an uplink have different bandwidths in a typical wireless communication system, use of only one carrier is considered for each of the downlink and the uplink. For example, a single-carrier wireless communication system may be provided, in which each of a downlink and an uplink has a single carrier and the bandwidths of the downlink and the uplink are generally symmetrical.
The International Telecommunication Union (ITU) requires that an IMT-Advanced candidate technology supports an extended bandwidth, compared to the legacy wireless communication systems. However, it is not easy to allocate a frequency having a broad band all around the world except some regions. Accordingly, as a technology for efficiently utilizing narrow frequency band fragments, Carrier Aggregation (CA, i.e. bandwidth aggregation) or spectrum aggregation has been developed to create the effect of using a logical broad band by physically aggregating a plurality of bands in the frequency domain.
CA is introduced to support increased throughput, to prevent a cost increase caused by the use of broadband Radio Frequency (RF) devices, and to ensure backward compatibility with the legacy systems. CA is a technology of enabling data exchange between a UE and an eNode B in a group of a plurality of carriers each having a bandwidth unit as defined in a legacy wireless communication system (i.e. a Long Term Evolution (LTE) system for an LTE-Advanced (LTE-A) system or an Institute of Electrical and Electronics Engineers (IEEE) 802.16e system for an IEEE 802.16m system). A carrier having a bandwidth unit as defined in the legacy wireless communication system is called a Component Carrier (CC). For example, although one CC supports a bandwidth of 5 MHz, 10 MHz, or 20 MHz, CA can support a system bandwidth of up to 100 MHz by aggregating up to 5 CCs.
The above-described CA technology can be applied to transmission and reception on a backhaul link between an eNode B and an RN and/or transmission and reception on an access link between an RN and a UE. However, a technique for configuring and assigning system transmission resources, which supports combination and/or adaptation of these two technologies, is yet to be specified.